It is a widely-spread falsehood by the NRA and assault weapon supporters that the AR-15 civilian versions of the M-16 are not “military-style assault weapons” because they are semi-automatic (you have to pull the trigger for each single round), while military versions support full automatic fire. In fact, M-14s, Most versions of M-16s, and several versions of the newer M-4, do NOT support full automatic fire.
The M-14 (predecessor to the M-16) was originally fully automatic, but due to the extreme difficulty soldiers had in controlling the weapon under full auto (due to the large 7.62 x 51 NATO round it was chambered for), the full automatic option was disabled.
Making its appearance during the Vietnam era, the M-16 came in several models, only some of which supported full auto on their selector switches. The M-16 was chambered for the smaller, lighter 5.56 x 45 NATO round, so the lighter ammo was easier to carry and the weapon easier to control on full auto. M-16 rifles were made in several models, some of which did NOT support full auto. The original M-16 and M-16A1 had a 3-position selector switch for safe/semi/full automatic. Concerned with the tendency of all but the most experienced combat vets to simply spray bullets around (the military still expends around 15,000 rounds in combat for every enemy death), the M-16A2 and its variants were designed without the capacity for full automatic fire. Their selector switch was safe/semi/3-round-burst (so-called “triple tap”). This was the most common M-16 used by the Marines in particular and many other units.
Whether M-16s supported full auto or 3-round-bursts, experienced combat riflemen in the field almost always used semi-auto (one shot with each trigger pull) to save their ammo, and relied on precision shooting instead of spraying for most combat situations. An M-16 with its selector switch on semi-auto is no different than the civilian AR-15 clones like the Bushmaster available today at gun shops, Wal-Marts, gun shows, etc.
Today’s M-4 carbine is a shorter weapon based on the M-16A2 and also has options with and without full automatic fire. The variation called the M-4A1 does support full auto. Ironically, one reason for the development of the M-4 was that the M-16 was considered too long and bulky for close combat, and the shorter, carbine-style M-4 was specifically designed for that use. This undermines the claim by assault rifle fans that M-16s are rational choices for defense against home invaders, with its similarities to close combat. M-4s, revolvers, and, even more so, shotguns, are far more rational choices. [Note: revolvers are simpler than semi-auto pistols and don’t carry nearly the risks of failure. For the ordinary person keeping a gun just for home protection, they are much easier to learn to use and maintain. There is no reason to keep something like a Glock 17 .9mm with magazine capacities of from 17 rounds (standard) up to 33 (plus one in the chamber if you want) unless you expect the entire local Hell’s Angels chapter to invade you.
So, it is just so much disingenuous hand-waving to claim that, because a Bushmaster and its civilian kin do not support fully automatic capabilities, they are not “true” military-style assault weapons. They most certainly are, and usually come with “picatinny rails” that can be used to equip them with all of the same accessories as military weapons – like flashlights, laser sights, advanced flash suppression, night-vision optics, and even sound suppressors (silencers) that the military rifles use.
An assault weapon is an assault weapon is an assault weapon – whether it is firing single rounds per trigger pull, three-round bursts, or full automatic. It was designed for combat and combat only.